fix(eink): remove scroll animation in eink mode and optimize eink detection (#3822)

* fix(eink): remove scroll animation in eink mode

* fix(android): fix startup ANR on e-ink devices from getprop subprocesses

Cargo.lock

@@ -27,6 +27,7 @@ dependencies = [
  "rand 0.8.5",
  "read-progress-stream",
  "reqwest 0.12.28",
+ "rsproperties",
  "serde",
  "serde_json",
  "tauri",
@@ -5080,6 +5081,12 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
 
+[[package]]
+name = "pretty-hex"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a65843dfefbafd3c879c683306959a6de478443ffe9c9adf02f5976432402d7"
+
 [[package]]
 name = "prettyplease"
 version = "0.2.37"
@@ -5835,6 +5842,20 @@ dependencies = [
  "byteorder",
 ]
 
+[[package]]
+name = "rsproperties"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b98d55abde44982a00d67a84809166ea8f5c143abc86818f555485f19766cfe4"
+dependencies = [
+ "log",
+ "pretty-hex",
+ "rustix 1.1.4",
+ "thiserror 2.0.18",
+ "zerocopy",
+ "zerocopy-derive",
+]
+
 [[package]]
 name = "rust-ini"
 version = "0.21.3"

apps/readest-app/src-tauri/Cargo.toml

@@ -78,3 +78,6 @@ tauri-plugin-single-instance = "2"
 tauri-plugin-updater = "2"
 tauri-plugin-window-state = "2"
 discord-rich-presence = "1.0.0"
+
+[target.'cfg(target_os = "android")'.dependencies]
+rsproperties = "0.3"

apps/readest-app/src-tauri/src/android/eink.rs

@@ -1,4 +1,4 @@
-use std::process::Command;
+use std::sync::OnceLock;
 
 /// Known e-ink device manufacturers and brands (case-insensitive matching)
 const EINK_MANUFACTURERS: &[&str] = &[
@@ -45,28 +45,21 @@ const EINK_MODELS: &[&str] = &[
     "max lumi",
 ];
 
-/// Get Android system property using getprop command
 fn get_system_property(prop: &str) -> Option<String> {
-    Command::new("getprop")
-        .arg(prop)
-        .output()
+    rsproperties::get::<String>(prop)
         .ok()
-        .and_then(|output| {
-            if output.status.success() {
-                let value = String::from_utf8_lossy(&output.stdout).trim().to_string();
-                if value.is_empty() {
-                    None
-                } else {
-                    Some(value)
-                }
-            } else {
-                None
-            }
-        })
+        .filter(|s| !s.is_empty())
 }
 
-/// Check if the current Android device is an e-ink device
+/// Check if the current Android device is an e-ink device.
+///
+/// The result is cached on first call so subsequent calls are free.
 pub fn is_eink_device() -> bool {
+    static IS_EINK: OnceLock<bool> = OnceLock::new();
+    *IS_EINK.get_or_init(detect_eink_device)
+}
+
+fn detect_eink_device() -> bool {
     // Get device manufacturer and model
     let manufacturer = get_system_property("ro.product.manufacturer")
         .or_else(|| get_system_property("ro.product.brand"))

apps/readest-app/src/app/reader/components/sidebar/TOCView.tsx

@@ -43,9 +43,10 @@ const TOCView: React.FC<{
   bookKey: string;
   toc: TOCItem[];
 }> = ({ bookKey, toc }) => {
-  const { getView, getProgress } = useReaderStore();
+  const { getView, getViewSettings, getProgress } = useReaderStore();
   const { sideBarBookKey, isSideBarVisible } = useSidebarStore();
   const progress = getProgress(bookKey);
+  const isEink = !!getViewSettings(bookKey)?.isEink;
 
   const [expandedItems, setExpandedItems] = useState<Set<string>>(() =>
     computeExpandedSet(toc, progress?.sectionHref),
@@ -131,14 +132,18 @@ const TOCView: React.FC<{
     const timer = setTimeout(() => {
       const idx = flatItems.findIndex((f) => f.item.href === activeHref);
       if (idx !== -1) {
+        // Eink displays ghost previous frames during smooth JS scroll
+        // animations; force an instant jump to avoid the artifact. A CSS-only
+        // fix is impossible because scrollTo({ behavior: 'smooth' }) overrides
+        // CSS scroll-behavior and is not a CSS transition.
         const distance = Math.abs(idx - visibleCenterRef.current);
-        const behavior = distance > 16 ? 'auto' : 'smooth';
+        const behavior = isEink || distance > 16 ? 'auto' : 'smooth';
         virtuosoRef.current?.scrollToIndex({ index: idx, align: 'center', behavior });
       }
       pendingScrollRef.current = false;
     }, 100);
     return () => clearTimeout(timer);
-  }, [flatItems, activeHref, isSideBarVisible]);
+  }, [flatItems, activeHref, isSideBarVisible, isEink]);
 
   return (
     <div ref={containerRef} className='toc-list rounded' role='tree'>

apps/readest-app/src/app/reader/hooks/useScrollToItem.ts

@@ -20,7 +20,11 @@ const useScrollToItem = (
     const isVisible = rect.top >= 0 && rect.bottom <= window.innerHeight;
 
     if (!isVisible) {
-      element.scrollIntoView({ behavior: 'smooth', block: 'center' });
+      // Eink displays ghost previous frames during smooth JS scroll animations;
+      // force an instant jump. scrollIntoView({ behavior: 'smooth' }) overrides
+      // CSS scroll-behavior, so a CSS-only fix via useEinkMode is impossible.
+      const isEink = document.documentElement.getAttribute('data-eink') === 'true';
+      element.scrollIntoView({ behavior: isEink ? 'auto' : 'smooth', block: 'center' });
     }
 
     if (isCurrent) {

apps/readest-app/src/services/settingsService.ts

@@ -39,13 +39,13 @@ export function getDefaultViewSettings(ctx: Context): ViewSettings {
     ...DEFAULT_BOOK_STYLE,
     ...DEFAULT_BOOK_FONT,
     ...DEFAULT_BOOK_LANGUAGE,
-    ...(ctx.isMobile ? DEFAULT_MOBILE_VIEW_SETTINGS : {}),
-    ...(ctx.isEink ? DEFAULT_EINK_VIEW_SETTINGS : {}),
-    ...(isCJKEnv() ? DEFAULT_CJK_VIEW_SETTINGS : {}),
     ...DEFAULT_VIEW_CONFIG,
     ...DEFAULT_TTS_CONFIG,
     ...DEFAULT_SCREEN_CONFIG,
     ...DEFAULT_ANNOTATOR_CONFIG,
+    ...(ctx.isMobile ? DEFAULT_MOBILE_VIEW_SETTINGS : {}),
+    ...(ctx.isEink ? DEFAULT_EINK_VIEW_SETTINGS : {}),
+    ...(isCJKEnv() ? DEFAULT_CJK_VIEW_SETTINGS : {}),
     ...{ ...DEFAULT_TRANSLATOR_CONFIG, translateTargetLang: getTargetLang() },
   };
 }